Kay began her journalism career as a book reviewer. During the 1990s, she joined the board and writing staff of the revived Cité libre. Afterward, Kay branched out into writing op/eds for the Post before becoming a columnist in 2003.[4]

In 2006 she was criticized for a series of articles accusing Quebec politicians of supporting Hezbollah during the 2006 Israel-Lebanon conflict. In 2007, the Quebec Press Council released a decision condemning Kay for "undue provocation" and "generalizations suitable to perpetuate prejudices".[5]

In 2007, she wrote a column titled "Not in my backyard, either" in which she criticized Hasidic Jews for not integrating into the neighbourhoods in which they live and for being "self-segregating" and "cult-like".[6] In 2008, she wrote another column criticizing Hasids in the Toronto area. She was accused of hating Jews as a result,[7] her own Jewishness notwithstanding.

In 2013, Kay published an article sympathising with Serena Williams' Rolling Stone statement regarding the Steubenville rape case.[8] In a response to a comment, she said, "Ours is not a rape culture. If it were, our girls would be walking around in burqas". Further debate over what constitutes rape culture came in February 2014 when Kay criticized universities for exaggerating the prevalence of rape.[9] Her claim that prudent women face a "statistically nugatory" chance of being assaulted was referred to as "irresponsible nonsense" by Toula Drimonis and Ethan Cox.[10]